linux-postmarketos-qcom-sdm845: use ZBOOT (MR 4542)

EFI booting with systemd-boot requires building the kernel with ZBOOT -
the EFI decompressor stub. However, this breaks the old Android booting.
Detect when ZBOOT is enabled and install both vmlinuz.efi as well as the
old gzipped kernel image.

To help make this upgrade more seamless, continue to support building
the kernel with ZBOOT disabled and just print a warning.

Disable module stripping - we compress them anyway and a recent kernel
change seems to have caused some bug here.

This is a packaging change that doesn't require rebuilding the kernel.
[ci:skip-vercheck]

device/community/linux-postmarketos-qcom-sdm845/APKBUILD

@@ -6,7 +6,7 @@
 _flavor="postmarketos-qcom-sdm845"
 pkgname=linux-$_flavor
 pkgver=6.5.5
-pkgrel=0
+pkgrel=1
 pkgdesc="Mainline Kernel fork for SDM845 devices"
 arch="aarch64"
 _carch="arm64"
@@ -39,8 +39,19 @@ build() {
 }
 
 package() {
-	install -Dm644 "$builddir/arch/$_carch/boot/Image.gz" \
-		"$pkgdir/boot/vmlinuz"
+	if [ -e "$builddir/arch/$_carch/boot/vmlinuz.efi" ]; then
+		# ZBOOT EFI decompressor for EFI booting
+		install -Dm644 "$builddir/arch/$_carch/boot/vmlinuz.efi" \
+			"$pkgdir/boot/linux.efi"
+
+		# Old GZIP'd kernel image for boot.img compatibility
+		install -Dm644 "$builddir/arch/$_carch/boot/vmlinuz" \
+			"$pkgdir/boot/vmlinuz"
+	else
+		echo "WARNING: CONFIG_ZBOOT not enabled!"
+		install -Dm644 "$builddir/arch/$_carch/boot/Image.gz" \
+			"$pkgdir/boot/vmlinuz"
+	fi
 
 	make modules_install dtbs_install \
 		ARCH="$_carch" \